Basic electricity:direct current :   electron flow-english    

 - Crowborough :  Audio Visual Source,   [19__]    
 - Videocassette;   19cm.    
 - Bergwall Production    .
<br/><br/> VHS/NTSC    
<br/><br/><label>ISBN: </label>20040000375    
<br/><br/><label>Subjects--Topical Terms: </label><br/>Electric circuits   <br/>Electron flow